In an effort to produce more variety for today’s highly competitive market, companies are designing and developing families of products — groups of related products derived from common product platforms — to simultaneously satisfy multiple customer requirements. After reviewing the state of the art in product family and product platform design, we describe the Product Platform Concept Exploration Method (PPCEM) for designing common product platforms that can be scaled or “stretched” into a suitable family of products. This paper extends previous work by the authors through the novel integration of physical programming within the PPCEM to enable the product family design problem to be formulated using physically meaningful terms and preferences. The design of a family of universal electric motors is presented to demonstrate the effectiveness of the proposed approach. Performance gains are achieved in the motor family by utilizing physical programming within the PPCEM when compared to previous results.